LOJ#3095. 「SNOI2019」字符串

如果两个串\(i,j\)比较\(i < j\)，如果离\(a_{i}\)最近的不同的数是\(a_{k}\)，如果\(j < k\)那么\(i\)排在\(j\)前面

否则的话如果\(a_{k} < a_{i}\)，那么\(i\)排在\(j\)前

于是写个比较函数扔到sort里就可以了

#include <bits/stdc++.h>

#define fi first

#define se second

#define pii pair<int,int>

#define mp make_pair

#define pb push_back

#define space putchar(' ')

#define enter putchar('\n')

#define eps 1e-10

#define MAXN 1000005

#define ba 47

//#define ivorysi

using namespace std;

typedef long long int64;

typedef unsigned int u32;

typedef double db;

template<class T>

void read(T &res) {

    res = 0;T f = 1;char c = getchar();

    while(c < '0' || c > '9') {

	if(c == '-') f = -1;

	c = getchar();

    }

    while(c >= '0' && c <= '9') {

	res = res * 10 +c - '0';

	c = getchar();

    }

    res *= f;

}

template<class T>

void out(T x) {

    if(x < 0) {x = -x;putchar('-');}

    if(x >= 10) {

	out(x / 10);

    }

    putchar('0' + x % 10);

}

int N,id[MAXN],nxt[MAXN];

char s[MAXN];

bool cmp(int a,int b) {

    bool f = 0;

    if(a > b) {f = 1;swap(a,b);}

    if(b < nxt[a]) f ^= 1;

    else {

	f ^= (s[nxt[a]] < s[a]);

    }

    return f;

}

void Solve() {

    read(N);

    scanf("%s",s + 1);

    for(int i = 1 ; i <= N ; ++i) {

	id[i] = i;

    }

    nxt[N] = N + 1;

    for(int i = N - 1 ; i >= 1 ; --i) {

	if(s[i + 1] != s[i]) nxt[i] = i + 1;

	else nxt[i] = nxt[i + 1];

    }

    sort(id + 1,id + N + 1,cmp);

    for(int i = 1 ; i <= N ; ++i) {

	out(id[i]);space;

    }

    enter;

}

int main() {

#ifdef ivorysi

    freopen("f1.in","r",stdin);

#endif

    Solve();

}